Power plant with steam cycle and with a high temperature thermal energy exchange system and method for manufacturing the power plant

ABSTRACT

A power plant with at least one steam cycle and with at least one high temperature thermal energy (heat) exchange system is provided. The high temperature thermal energy exchange system includes at least one heat exchange chamber with chamber boundaries which surround at least one heat exchange chamber interior of the heat exchange chamber. The chamber boundaries include at least one inlet opening for guiding in an inflow of at least one heat transfer fluid into the heat exchange chamber interior and at least one outlet opening for guiding out an outflow of the heat transfer fluid out of the heat exchange chamber interior; at least one heat storage material is arranged in the heat exchange chamber interior such that a heat exchange flow of the heat transfer fluid through the heat exchange chamber interior causes a heat exchange between the heat storage material and the heat transfer fluid.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to PCT Application No.PCT/EP2015/055957, having a filing date of Mar. 20, 2015, based off ofEuropean application No. EP14187091 having a filing date of Sep. 30,2014, the entire contents of all of which are hereby incorporated byreference.

FIELD OF TECHNOLOGY

The following relates to a power plant with steam cycle and with a hightemperature thermal energy exchange system and a method formanufacturing the power plant.

BACKGROUND

Despite the integration of renewable energy into the public electricenergy system (power grid) a large share of electricity is nowadaysstill generated by fossil energy sources. But the global climate changerequires the further development of renewable energies.

The energy output of renewable energy sources like wind and solar is notconstant throughout a day or throughout a year. Consequently,electricity which is generated by utilizing energy from renewable energysources fluctuates.

In order to handle this fluctuating electricity energy storage units aredeveloped. Such energy storage units are a) mechanical storage unitse.g. pumped hydro storage, compressed air storage or flywheels, (b)chemical energy storage units e.g. storage of hydrogen, batteries andorganic molecular storage, (c) magnetic energy storage units, and (d)thermal energy storage units with water or molten salts.

However, only pumped hydro storage is already today well-established andmatured as a large scale energy storage technology. All other storagetechnologies are lacking capability to store electric energy at lowcost, whereas pumped hydro storage is geographically limited to certainregions (sufficient geodetic heights).

SUMMARY

An aspect relates to providing an efficient, cost effective and reliablesolution for storing (absorbing) energy and releasing the stored(absorbed) energy in an existing power plant with a steam cycle.

A power plant with at least one steam cycle and with at least one hightemperature thermal energy (heat) exchange system is provided, with atleast one heat exchange chamber with chamber boundaries which surroundat least one heat exchange chamber interior of the heat exchangechamber. The chamber boundaries comprise at least one inlet opening forguiding in an inflow of at least one heat transfer fluid into the heatexchange chamber interior and at least one outlet opening for guidingout an outflow of the heat transfer fluid out of the heat exchangechamber interior; at least one heat storage material is arranged in theheat exchange chamber interior such that a heat exchange flow of theheat transfer fluid through the heat exchange chamber interior causes aheat exchange between the heat storage material and the heat transferfluid and the high temperature thermal energy exchange system comprisesat least one retrofit component with which the power plant with steamcycle is equipped. The heat is thermal energy. For instance, the hightemperature thermal energy exchange system can be used partly orcompletely for a retrofit procedure.

In addition to the power plant, a method for manufacturing the powerplant with the steam cycle with the following manufacturing step isprovided: retrofitting an existing power plant which comprises at leastone steam cycle with at least one high temperature thermal energyexchange system. The existing power plant is retrofitted by the hightemperature thermal energy exchange system. By this retrofittingprocedure, new installations can be incorporated into the existing powerplant. Preferably, existing installations (e.g. heat exchange systems)can be used. Preferably, for the retrofitting a replacement of at leastone steam cycle component of the steam cycle by the high temperaturethermal energy exchange system is carried out. The existing power plantcan be every kind of thermal power plant like nuclear power plant, gaspower plant, steam power plants or a combination thereof.

The power plant with steam cycle is used for a method for transformingenergy, wherein in an operating mode of the high temperature thermalenergy exchange system a heat exchange flow of heat transfer fluid isguided through the heat exchange chamber interior, whereby a heatexchange between the heat storage material and the heat transfer fluidis caused. Heat exchange between the heat transfer fluid and the heatstorage material occurs. The operating mode is selected from the groupconsisting of charging mode and discharging mode. During the chargingmode a heat transfer from the heat transfer fluid to the heat storagematerial takes place whereas during the discharging mode a heat transferfrom the heat storage material to the heat transfer fluid takes place.

In order to increase the flexibility the steam cycle of fossil firedpower plants (or nuclear power plants, etc.) can be combined with thehigh temperature thermal energy exchange system proposed here. Eitherthe installed equipment is solely used to generate electrical energywith the stored thermal energy in a heat recovery process like in CCPP(combined cycle power plant) or the high temperature thermal energyexchange system is used to increase the flexibility of a thermal powerplant. In the latter case the boiler is operated with fuel when fuelcosts are lower than electricity costs and the storage is charged ifelectricity prices are low. Charging can take place during a period ofexcess production of energy.

The discharging mode can be realized when electricity prices and demandare high or when the production of renewable energies is low. Wellsuited are CCPP since their heat recovery steam generator (HRSG) issimilar to the application proposed here. Nevertheless, hard coal, oil,gas, waste incineration, wood or lignite fired power plants can be usedsince the heater device can be designed for high temperature to matchthe temperatures used in the steam generator. In a hybrid mode the fuelcan be used to increase the temperature from the temperature level ofthe storage to the operating temperature of the original furnace orboiler design.

The heat exchange chamber is a space, cavity, excavation or a housing inwhich the heat storage material is located. Within the heat exchangechamber the heat exchange takes place. In order to provide an efficientheat exchange, the heat exchange chamber is preferably thermallyinsulated against the surroundings. The loss of thermal energy isreduced by the thermal insulation.

The heat transfer fluid is guided (led) into the heat exchange chamberinterior via the inlet opening and is guided out of the heat exchangechamber interior via the outlet opening. There is an inlet area of thechamber boundary with the inlet opening and there is an outlet area ofthe chamber boundary with the outlet opening.

For the guiding of the heat transfer fluid into the heat exchangechamber and for the guiding of the heat transfer fluid out of the heatexchange chamber a pipe system (or channel system, ducting system) isused. This pipe system can be closed (with a closed loop) or can be open(with an open loop). For instance the heat transfer fluid is ambient(air of the environment). The loop is an open loop. Air from theenvironment is introduced into the high temperature thermal energyexchange system and air of the high temperature thermal energy exchangesystem is released to the surroundings. There is an air exchange duringthe operation of the high temperature thermal energy exchange system. Incontrast to that, there is no air exchange or a selectively adjustableair exchange during the operation in a closed loop. This has followingspecific advantage: In a situation with an almost completely chargedheat storage material, heat transfer fluid with remaining heat isreleased to the environment in an open loop. The remaining heat is lost.In contrast to that, in a closed loop this heat transfer fluid withremaining heat stays in the high temperature thermal energy exchangesystem. The remaining heat is not lost. Therefore, in a preferredembodiment, a closed loop is implemented and wherein the inflowcomprises the outflow. The outflow is guided back to the inlet opening.

Depending on the operating mode, a specific opening can have thefunction of an inlet opening or the function of an outlet opening. Theflow direction of the heat exchange flow depends on the operating mode.Preferably, during the charging mode the heat exchange flow is directedin a charging mode direction, during the discharging mode the heatexchange flow is directed in a discharging mode direction and thecharging mode direction and the discharging mode direction are oppositeto each other (countercurrent). But, a change of the directions of theheat exchange flow is not necessary. Charging mode direction anddischarging mode direction comprise the same direction (co-current). Ina different operational use the main flow direction of the heat transferfluid is the same for the charging mode and the discharging mode.

In countercurrent operation, switching from the charging mode to thedischarging mode the direction of the exchange flow through the heatexchange chamber interior is reversed and consequently, the function ofthe openings (inlet opening, outlet opening) as well as a relativetemperature (cold or hot) at the opening is reversed, too. With such asolution it is especially advantageous to use the same heat transferfluid for the charging mode and for the discharging mode. But of course,different heat transfer fluids for the charging mode and the dischargingmode can be used, too.

The high temperature thermal energy exchange system is especiallyadapted for operation at high temperatures. Therefore, in a preferredembodiment, an operating temperature of the operating mode is selectedfrom the range between 300° C. and 1000° C., preferably selected fromthe range between 500° C. and 1000° C., more preferably selected fromthe range between 600° C. and 1000° C., 650° C. to 1000° C. and mostpreferably between 700° C. and 1000° C. A deviation of the temperatureranges is possible. In this context, very advantageous is an upper limitof the temperature range of 900° C. and most preferably an upper limitof the temperature range of 800° C.

The heat storage material can be liquid and/or solid. For instance, acore of the heat storage material is solid and a coating of this solidcore is liquid. Such a liquid coating can comprise ionic liquid.

The solid material comprises preferably bulk material. Mixtures ofdifferent liquid materials and different solid materials are possible aswell as mixtures of liquid and solid materials.

It is possible that the heat storage material is a thermo-chemicalenergy storage material: Energy can be stored via an endothermicreaction whereas energy can be released via an exothermic reaction. Sucha thermo chemical storage is for instance the calcium oxide/calciumhydroxide system. These heat storage materials can be arranged inspecific containers out of non-reactive container material. Non-reactivemeans that no chemical reaction between the heat storage material andthe container material takes place during the heat exchange process.

In a preferred embodiment, the heat storage material comprises at leastone chemically and/or physically stable material. In the range of theoperational temperature the heat storage material does not change itsphysical and/or chemical properties. A physically stable material doesnot change its physical properties during the heat exchange. Forinstance, the heat storage material remains in a solid state in theoperating temperature range. A chemically stable material does notchange its chemical composition during the heat exchange. For instance,such a chemically stable material is a phase change material (PCM).

Moreover, a complex high temperature thermal exchange system withdifferent heat exchange chambers with different heat storage materialsand/or different heat transfer fluids is possible, too. For Instance, athermal exchange unit with stones as heat storage material and a thermalexchange unit with a phase change material as a heat storage materialare combined together.

In a preferred embodiment, the heat storage material comprises sandand/or stones. The stones can be natural stones or artificial stones.Mixtures thereof are possible, too. Artificial stones can consist ofcontainers which are filled with heat storage material. This heatstorage material is for instance a phase-change material or athermo-chemical storage material (see above).

Preferably, the stones comprise gravels (pebbles), rubbles and/or grit(splits). The artificial material comprises preferably clinkers orceramics. Again, mixtures of the mentioned materials are possible, too.

In order to provide a cheap energy storage material it is advantageousto use waste material. Therefore, in a preferred embodiment, theartificial material comprises at least on by-product of an industrialprocess. For instance, the by-product is iron silicate. Iron silicateorigins from a slag of copper production.

In a preferred embodiment, heat exchange channels are embedded in theheat storage material for guiding of the heat exchange flow through theheat exchange chamber interior. The heat storage material forms a heatexchange bed. The heat exchange bed comprises the heat exchangechannels. The heat exchange channels are embedded into the heat storagebed such that the heat exchange flow of the heat transfer fluid throughthe heat exchange channels causes the heat exchange between the heatstorage material and the heat transfer fluid. The heat exchange channelscan be formed by interspaces (gaps) of the heat storage material. Forinstance, the heat storage material comprises stones. The stones formthe heat exchange bed with the heat exchange channels. In addition oralternatively, the heat storage material is porous. Open pores of theheat storage material form the heat exchange channels.

In a preferred embodiment, the high temperature thermal energy exchangesystem is equipped with at least one flow adjusting element foradjusting the heat exchange flow of the heat transfer fluid through theheat exchange chamber interior, the inflow of the heat transfer fluidinto the heat exchange chamber interior and/or the outflow of the heattransfer fluid out of the heat exchange chamber interior. With the aidof the flow adjusting element it is possible to adjust a temperaturedistribution in the heat exchange chamber interior and within the heatstorage material respectively. The use of a number of flow adjustingelements is advantageous for a fine tuning of the heat exchange flow andconsequently for a fine tuning of the temperature distribution in theheat storage material.

Preferably, the flow adjusting element comprises at least one activefluid motion device (with a corresponding software system) which isselected from the group consisting of blower, fan and pump and/or theflow adjusting element comprises at least one passive fluid controldevice which is selected from the group consisting of activatable bypasspipe, nozzle, flap and valve. A multitude of these devices are possibleas well as a combination of these devices. With the aid of such devicesthe heat exchange flow can be modified such that the heat exchangeoccurs efficiently. In addition, flow adjusting elements can be arrangedserially or in parallel. For instance, two flaps are arranged at twoinlet openings in order to adjust the inflows of the heat transfer fluidinto the heat exchange chamber and consequently in order to adjust thetemperature distribution in the heat exchange chamber.

The flow adjusting element is arranged in the heat exchange chamber,downstream of the heat exchange chamber and/or upstream of the heatexchange chamber.

In the context of the active fluid motion devices it is advantageousthat driving units of the active fluid motion devices like electricmotors and electrical equipment are located outside of the (possiblyvery hot) heat exchange flow.

The special advantage of passive control devices is that they are cheap.In addition, passive control devices are very reliable.

The heat exchange chamber is a vertical heat exchange chamber and/or ahorizontal heat exchange chamber.

The term “horizontal heat exchange chamber” implies a horizontal main(average) flow of the heat transfer fluid through the heat exchangechamber interior. The flow direction of the horizontal main flow isessentially parallel to the average surface of the earth. The horizontaldirection is essentially a perpendicular direction to the direction ofthe gravity force which affects the heat transfer fluid. Perpendicularmeans in this context that deviations from the perpendicularity of up to20° and preferably deviations of up to 10° are possible.

The special advantage of passive control devices is that they are cheap.In addition, passive control devices are very reliable.

The heat exchange chamber is a vertical heat exchange chamber and/or ahorizontal heat exchange chamber.

The term “horizontal heat exchange chamber” implies a horizontal main(average) flow of the heat transfer fluid through the heat exchangechamber interior. The flow direction of the horizontal main flow isessentially parallel to the average surface of the earth. The horizontaldirection is essentially a perpendicular direction to the direction ofthe gravity force which affects the heat transfer fluid. Perpendicularmeans in this context that deviations from the perpendicularity of up to20° and preferably deviations of up to 10° are possible.

A horizontally oriented direction of the heat exchange flow can beachieved by lateral inlet openings and/or lateral outlet openings. Thehorizontal heat exchange chamber comprises these openings in its sidechamber boundaries. In addition, with the aid of an active fluid motioncontrol device like a blower or a pump the heat exchange flow in theheat exchange chamber interior is caused. The heat transfer fluid isblown or pumped into the heat exchange chamber interior or is pumped orsucked out of the heat exchange chamber interior.

In contrast to the term “horizontal heat exchange chamber”, the term“vertical heat exchange chamber” implies a vertical main flow of theheat transfer fluid through the heat exchange chamber interior. Forinstance, the operating mode is the charging mode. In a vertical heatexchange chamber the heat exchange flow is preferably directed downwards(top down) during the charging mode. The vertical main flow (essentiallyparallel but in the opposite direction to the direction of gravityforce) can be caused by an active fluid motion device (blower or pump).The inlet opening is located at a top of the heat exchange chamber andthe outlet opening is located at a bottom of the heat exchange chamber.

Based on natural convection, in a vertical heat exchange chamber thetemperature of the heat storage material along a cross sectionperpendicular to the flow direction of the heat transfer fluid isapproximately the same (horizontal isothermal lines).

In contrast to that, in a horizontal heat exchange chamber due tonatural convection the temperature of the heat storage material alongthe cross section perpendicular to the flow direction of the heattransfer fluid (see below) can differ (inclined isothermal lines).

It has to be noted that the terms “horizontal” and “vertical” areindependent from the dimensions of the heat exchange chamber and itsorientation. Decisive is the direction of the flow of the heat transferfluid through the heat exchange chamber interior. For instance, a“horizontal heat exchange chamber” can have a chamber length which isless than the chamber height of the heat exchange chamber.

Besides pure vertical and horizontal heat exchange chambers, a mixtureof “vertical heat exchange chamber” and “horizontal heat exchangechamber” is possible, too. In such a heat exchange chamber, the mainflow of the heat transfer fluid is the result of horizontal and verticalmovement of the heat transfer fluid through the heat exchange chamberinterior.

In a preferred embodiment, at least two inlet openings are arrangedvertically to each other and/or at least two outlet openings arearranged vertically to each other. Openings are arranged above eachother. By this measure it is possible to influence a verticaldistribution of heat exchange flows in order to improve a temperaturedistribution (temperature front) in the heat storage material and heatexchange chamber interior respectively. Isothermal lines perpendicularto the flow direction are influenced.

The temperature front is defined by neighboring cold and hot areas ofthe heat storage material in the heat exchange chamber interior causedby the flow of the heat transfer fluid through the heat exchange chamberinterior. The temperature front is aligned perpendicular to therespective flow direction of the heat exchange flow through the heatexchange chamber. During the charging mode the heat exchange flow isdirected in a charging mode direction wherein the temperature frontmoves along this charging mode direction. In contrast to that, duringthe discharging mode the heat exchange flow is directed in thedischarging mode direction (opposite to the charging mode direction)wherein the temperature front moves along the discharging modedirection. In both cases, the temperature front of the heat exchangechamber is migrating through the heat exchange chamber to the respectivehot/cold ends of the heat exchange chamber. It is to be noted that incase of countercurrent operation, the hot (hot opening) end remains thehot end (hot opening), independently from the mode (charging ordischarging mode).

The temperature front is a zone of strong temperature gradient in theheat storage material, i.e. high temperature difference between hot andcold areas. In this application it separates the hot (charged withthermal energy) and the cold (not charged) zone in the heat exchangechamber within the heat storage material. The temperature front developsdue to the transfer of thermal energy from the heat transfer fluid tothe heat storage material during charging and from the heat storagematerial to the heat transfer fluid during discharging. Isothermalzones/lines develop ideally (e.g. without the influence of gravitation)perpendicular to the main flow direction, i.e. zones/lines of constanttemperature.

In order to optimize the efficiency of the high temperature thermalenergy exchange system it is advantageous to ensure a uniformtemperature front. There are just small variations concerning thetemperature gradients perpendicular to the flow direction. In a verticalheat exchange chamber with a flow direction top down, the temperaturefront is nearly uniform due to natural convection. So, in this caseadditional measures are not necessary. In contrast to that, naturalconvection leads to a non-uniform temperature front in a horizontal heatexchange chamber. So, in this case additional measures could bemeaningful (like usage of more openings or usage of more flow adjustingelements).

In order to optimize the efficiency of the high temperature thermalenergy exchange system it advantageous to ensure a uniform temperaturefront. There are just small variations concerning the temperaturegradients perpendicular to the flow direction. In a vertical heatexchange chamber with a flow direction top down, the temperature frontis nearly uniform due to natural convection. So, in this case additionalmeasures are not necessary. In contrast to that, natural convectionleads to a non-uniform temperature front in a horizontal heat exchangechamber. So, in this case additional measures could be meaningful (likeusage of more openings or usage of more flow adjusting elements).

For the case that the heat exchange chamber comprises a number of inletopenings it is very advantageous to arrange a described transition areain at least one of the inlet openings. Preferably, a number of inletopenings or every inlet opening comprises its individual transitionarea.

The transition area with the outlet opening can be tapered, too: Atapering of the chamber opening to the outlet opening is implemented. Bythis measure the guiding of heat flow out of the interior of the heatexchange chamber is simplified.

In a configuration where the flow direction of charging and dischargingare opposite the tapering of the transition area at the inlet openingand the tapering of the transition area at the outlet opening ensure adesired flow distribution of the heat transfer fluid in both operatingmodes.

In this context the use of a short transition area is very advantageous.For instance, the short transition area comprises a dimension which isless than 50% of a heat exchange chamber length. For instance, thedimension is about 20% of the heat exchange chamber length. The lengthis the heat exchange chamber dimension that is parallel to the main flowdirection of the heat transfer fluid through the heat exchange chamber.But of course, the dimension of the transition area is dependent on anumber of features of the complete system, e.g. temperature of the heattransfer fluid, mass flow of the heat exchange flow, speed of the heatexchange flow at the relevant opening, etc.

In order to save space and in order to reduce the surface-volume ratiofor a reduced heat loss, it is advantageous to implement a transitionarea as short as possible. The result is a short transition channel forguiding the inflow into the heat exchange chamber interior. Besides anefficient usage of the capacity of the heat exchange chamber a low spacerequirement is connected to this solution.

Preferably, the heat exchange chamber comprises a cylindrically shapedchamber boundary. For instance, the chamber boundary which comprises theinlet opening is formed as a circular cylinder and/or the chamberboundary with the outlet opening is formed as a circular cylinder. Suchshapes lead to best surface-volume ratios.

The heat transfer fluid is selected from the group consisting of aliquid and a gas. The gas is selected from the group consisting ofinorganic gas and/or organic gas. The inorganic gas is preferably air.Mixtures of different liquids are possible as well as mixtures ofdifferent gases.

Preferably, the heat transfer fluid comprises a gas at ambient gaspressure. Preferably, the gas at the ambient pressure is air. Theambient pressure (900 hPa to 1,100 hPa) varies such that the heatexchange flow through the heat exchange chamber interior is caused.

In a preferred embodiment, the high temperature thermal energy storagesystem is equipped with at least one charging unit for heating the heattransfer fluid. This charging unit is preferably located upstream of theheat exchange chamber (before the heated heat transfer fluid enters theheat exchange chamber).

Preferably, the charging unit comprises at least one electrical heatingdevice which is selected from the group consisting of resistance heater,inductive heater, emitter of electromagnetic radiation and heat pump.The electromagnetic radiation is preferably infrared radiation. With theaid of the resistance heater electricity is transformed into thermalenergy and transferred to the heat transfer fluid. Preferably, theresistance heater or a number of resistance heaters are located in theheat exchange flow. Preferably, the resistance heater comprises a largeheat exchange area for an efficient heat exchange from the resistanceheater to the heat transfer fluid. For instance, the large heat exchangearea is formed by grid of the resistance heater. A meander shapedresistance is possible, too. With such a measure, the heat transfer tothe heat transfer fluid is enhanced. In addition, the possibility of thenot desired occurrence of hot spots within the resistance heater isreduced.

The heat exchange surface of the resistance heater is located in theheat exchange flow whereas control units and/or propulsion units of theresistance heater are located outside of the heat exchange flow.Preferably, such a unit is located at a respective cold area of the hightemperature thermal energy exchange system.

A combination of different electrical heating devices is possible.Alternatively or in addition, a heating up of the heat transfer fluidwith the aid of waste energy or combustion heat is possible, too.

In a preferred embodiment, the high temperature thermal energy exchangesystem is equipped with at least one discharging unit for dischargingthe heat transfer fluid of the outflow from heat for production ofelectricity. Thermal energy is released (removed from the heat transferfluid) and is transformed into electricity. The thermal energy isespecially used for the driving of a water/steam cycle.

In a preferred embodiment, the high temperature thermal energy exchangesystem is equipped with at least one measuring device for determining acharge status of the high temperature thermal energy exchange system.Preferably, the mentioned measuring device for determining a chargestatus of the high temperature thermal energy exchange system is athermocouple. The thermocouple is a temperature measuring device whichis based on the Seebeck effect. Alternatively, the temperature measuringdevice is based on electrical resistance.

For instance, the charge status of the high temperature thermal energyexchange system comprises the degree of the charging of the heat storagematerial with heat. With the aid of the measured charge status theoperating mode (charging mode or discharging mode) can be monitored.Information about the charge status can be used for the process controlof the operating modes. The charge status or state of charge refers tothe energy content of the high temperature thermal exchange system whichis related to the temperature of the heat storage material. If a largeshare of the heat storage material comprises a high temperature thestate of charge or charge status is higher than if a small share of theheat storage materials at a high temperature.

In this context it is advantageous to use a number of such measuringdevices. Preferably, these measuring devices are distributed over theheat exchange chamber.

The heat exchange chamber can comprise large dimensions. Preferably, alength of the heat exchange chamber is selected from the range between20 m-250 m, a width of the heat exchange chamber is selected from therange between 20 m-250 m and a height of heat exchange chamber isselected from the range of 10 m-60 m.

For the charging cycle and/or for the discharging cycle the hightemperature thermal energy exchange system comprises preferably aparticle filter or other means to remove particles from the heattransfer fluid, for instance a cyclone particle remove system. Theremoving of particles servers the purpose of efficient heat transfer,avoid deposition of the particles, avoid cloaking and avoid possiblefires. It is possible to use this filter device just for commissioningpurposes. In this case, after the initial operation the filter device isremoved.

Due to high temperatures the high temperature thermal energy exchangesystem comprises preferably a pipe system with compensation units forbalancing different thermal induced dimension changes. Thermal mismatchdoes not result in a damage of the pipe system. This leads to a highreliability.

In a preferred embodiment, the power plant is a hybrid power plant witha thermal energy producing unit, wherein produced thermal energy fromthe thermal energy producing unit and/or stored thermal energy of thehigh temperature thermal energy exchange system can be used for drivingthe steam cycle.

The hybrid power plant comprises a conventional power plant like fossildriven power plant (gas or coal power plant), CCPP (combined cycle powerplant) or nuclear power plant. These power plants produce thermal energydirectly. In addition, excess electricity is transformed into thermalenergy in a charging mode (see above) which can be stored and which canbe released with the aid of the high temperature thermal energy exchangesystem.

With embodiments of the invention following specific advantages areachieved:

With the aid embodiments of the invention an existing power plant withsteam cycle is retrofitted by the high temperature thermal energyexchange system. Thereby existing installations can be used.

With the aid of the high temperature thermal energy exchange systemenergy can be stored and can be released efficiently. Excess electricityis used for the charging mode. Excess electricity is transformed intothermal energy which is stored. During the discharging mode thermalenergy is transformed into electricity, e.g. with the aid of a watersteam cycle. This transformation is very efficient due to hightemperatures provided by the high temperature exchange system.Electricity from the discharge mode is available during periods of highelectricity consumption and high demand (of consumers or of the energymarket).

Usually, the location of production of electricity with the aid fromrenewable energy sources such as onshore and offshore wind does notcoincide with the region of high power consumption. Weak grid nodepoints can cause a grid overload since they were designed for a constantbase load and not for fluctuating renewable energy. The excess energythat exceeds the capacity of the grid can reach up to 20%. In this casethe renewable energy sources have to be curtailed or even shutdown. Withembodiments of the invention an efficient storage of the excesselectricity is possible.

Thermal energy on a high temperature level can be stored over a longperiod of time. The high temperature thermal energy exchange systemcould deliver heat for more than 10 hours up to 10 days. The hightemperature level in this kind of storages can be more than 600° C. andit can be directly used for reconversion in a water steam cycle. Theelectrification of the stored thermal energy via the water steam cycledoes not depend on fuel like gas or coal and hence it is CO₂ emissionfree.

The high temperature thermal energy exchange system offers a higherenergy density compared to other storage technologies. This means thatmore energy can be stored in a smaller volume. In addition, bulk heatstorage materials are much cheaper and cost effective than molten saltsor phase change materials which are currently developed.

With the aid of a charging unit with an electrical heating device veryhigh temperatures of the heat transfer fluid are available.

Due to high temperatures an additional heating up for subsequentelectrification processes, e.g. additional heating up of steam of awater/steam cycle is not necessary.

The used heat storage materials are simple and regionally availablenatural products like basalt stones. By-products and waste materialsfrom industrial processes e.g. iron silicate slag from copper productionare possible storage materials as well. This reduces the costs andcauses short transport distances.

The high temperature thermal energy exchange system can be operatedunder ambient pressure (heat transfer fluid at ambient pressure). So,there is no need for installing pressure units in view of the heattransfer fluid. It is easier to reach a necessary reliability of thehigh temperature thermal energy exchange system. In addition, highpressure units would be expensive.

The stored thermal energy could be used for ORC (Organic Rankine Cycle)power plants. These power plants operate at relatively low operatingtemperatures. But preferably, the stored thermal energy is used forsteam power plants. Due to the high load capacity and the high possibleoperating temperatures of the high temperature thermal energy exchangesystem the working fluid (steam) of the steam power plant can beoperated at high temperatures (steam parameter). This results in a highefficiency of the steam cycle of the steam power plant.

Preferably, the high temperature thermal energy exchange systemcomprises a pipe system with compensation units (e.g. expansion joints)for balancing different thermal induced dimension changes (thermaldynamic loads). Thermal mismatch does not result in a damage of the pipesystem. This leads to a high reliability. Alternatively or in addition,the pipe system comprises thermally insulated components, like channelswhich are insulated from the inside.

Generally, there is a wide use of the high temperature thermal energyexchange system for this high quality heat. It is useable not only forwater steam cycles, it can also be used for industrial or power plantprocesses or for district heating or for industrial steam.

BRIEF DESCRIPTION

Some of the embodiments will be described in detail, with reference tothe following figures, wherein like designations denote like members,wherein:

FIGS. 1 to 4 show different high temperature thermal energy exchangesystems.

FIG. 2A shows a vertical heat exchange chamber in a discharging mode;

FIG. 2B shows the vertical heat exchange chamber of FIG. 2A in acharging mode;

FIG. 3 show horizontal heat exchange chambers;

FIG. 4 show horizontal heat exchange chambers;

FIG. 5A shows vertical heat exchange chambers;

FIG. 5B shows vertical heat exchange chambers;

FIG. 6A shows vertical heat exchange chambers;

FIG. 6B shows vertical heat exchange chambers;

FIG. 6C shows high temperature thermal energy exchange systems withdifferent thermal insulations of the heat exchange chamber;

FIG. 7 shows a complete high temperature thermal energy exchange system;

FIG. 8 shows power plants which are retrofitted with a high temperaturethermal energy exchange system;

FIG. 9 shows power plants which are retrofitted with a high temperaturethermal energy exchange system;

FIG. 10 shows power plants which are retrofitted with a high temperaturethermal energy exchange system; and

FIG. 11 shows power plants which are retrofitted with a high temperaturethermal energy exchange system.

DETAILED DESCRIPTION

Given is a power plant 100 with steam cycle 1003 with a least one hightemperature thermal energy exchange system 1 with at least one heatexchange chamber 11 with chamber boundaries 111 which surround at leastone heat exchange chamber interior 112 of the heat exchange chamber 11.

The high temperature thermal energy exchange system 1 comprises a heatexchange chamber 11 on a high temperature level which will be chargedand discharged with thermal energy via a heat transfer fluid 13 andstored in the heat storage material 121.

The temperature level of the stored heat is significantly highercompared to methods applied so far to increase the efficiency. Thetemperature level lies between 300° C. and 800° C., preferably between550° C. and 650° C. The thermal capacity of the high temperature thermalenergy exchange system lies in the range between 0.3 GWh and 100 GWh,which causes a thermal power of 50 MW.

The high temperature thermal energy exchange system 1 comprises at leastone heat exchange chamber 11 with chamber boundaries 111 which surroundat least one heat exchange chamber interior 112 of the heat exchangechamber 11. The heat exchange chamber is a horizontal heat exchangechamber 114.

The chamber boundaries 111 comprise at least one inlet opening 1111 forguiding in an inflow 132 of at least one heat transfer fluid 131 intothe heat exchange chamber interior 112 and at least one outlet opening1112 for guiding an outflow 133 of the heat transfer fluid out of theheat exchange chamber interior 112. At least one heat storage material121 is arranged in the heat exchange chamber interior 112 such that aheat exchange flow 13 of the heat transfer fluid 131 through the heatexchange chamber interior 112 causes a heat exchange between the heatstorage material 121 and the heat transfer fluid 131.

The heat exchange chamber is at least partly integrated in the earth. Analternative embodiment of the high temperature thermal energy exchangesystem comprises a completely integrated heat exchange chamber.

The high temperature thermal energy exchange system 1 is equipped with anumber of measuring devices 1500 for determining a charge status of thehigh temperature thermal energy exchange system 1. These measuringdevices are distributed mainly in the heat exchange chamber 11.

The heat exchange chamber 11 is thermally insulated against thesurrounding. There is a thermal insulation unit 300.

Different thermal insulation possibilities (thermal insulation stacks)are shown in FIGS. 6A, 6B and 6C. Concerning FIG. 6A the insulation unit300 comprises a first insulation cover sheet 301. This first insulationcover sheet comprises gas concrete, for instance Ytong®. Alternativelythis first insulation cover sheet comprises bricks, clay, ceramics,clinker, concrete, plaster, fiber reinforced plaster, and/or metal.

The next insulation layer 302 comprises mineral wool and/or rock wool.Alternatively this insulation layer 302 comprises foamed clay or glassconcrete. Mixtures of these materials are possible, too.

A third insulation layer 303 completes the insulation unit: This thirdinsulation layer 303 has the function of a supporting structure andcomprises gas concrete (for instance Ytong® or clay), clinker, concrete,plaster, fiber reinforced plaster and/or metal.

Alternatively, the first insulation layer 301 is omitted (FIG. 6B).

In a further alternative solution the thermal insulation unit 300comprises an additional intermediate insulation cover layer 304 (FIG.6C). This additional cover layer comprises gas concrete, clay orceramics and has the function of an additional supporting structure.

Exemplarily, the length 118 of the horizontal heat exchange chamber 11is about 200 m, the height 119 of the heat exchange chamber 11 is about10 m and the width of the heat exchange chamber 11 is about 50 m.

Alternatively, a vertical heat exchange chamber 113 is used (FIGS. 2Aand 2B). For instance, the height 120 of this vertical heat exchangechamber 113 is about 40 m, a width 119 about 20 m and a length of about40 m.

Alternatively, cylindrically shaped heat exchange chambers 113 are used.

The proposed high temperature thermal energy exchange system will storeenergy on a high temperature level, which can be used during dischargingto produce steam in a water steam cycle for reconversion into electricalenergy. Therefore, one or several heat exchange chambers filled withsolid heat storage material are used. The solid heat storage materialcould be bulk storages material with sand, stones or gravels, rubbles,splits, clinkers, ceramics, slag and other bulk materials, for examplebasalt or iron silicate slag.

The solid materials can be used alone or can be mixed with other heatstorage materials (e.g. due to limited availability of materials, inorder to improve the flow behavior of the heat exchange flow of the heattransfer fluid through the heat exchange chamber interior or in order toimprove the heat exchange between the heat storage material and the heattransfer fluid) for the use in the high temperature thermal energyexchange system. Different particle sizes or mixture of differentparticle sizes (improving flow behavior and energy density) can be used,too. As a result, the filling of the heat exchange chamber with heatstorage material can be homogenous or inhomogeneous.

This solid bulk material is heated up and stores the thermal energy overa long time period. The shape and the arrangement of one or several heatexchange chambers with the heat storage material are according to theusage and the integration in a certain system. The shape of the basearea of the heat exchange chamber depends on whether the heat exchangechamber(s) will be built vertically (no negative effect of naturalconvection) or horizontally (simple construction and incident flow,adaption to local conditions) as shown in FIGS. 1 and 2A and 2B. Thecross section of the heat exchange chamber will be a trapezoid, if theheat exchange chamber is horizontal).

In both cases (horizontal heat exchange chamber and vertical heatexchange chamber), there is a transition area 116 of the heat exchangechamber 11 with a tapering profile 1161. Thereby an opening diameter1113 of the opening 1111 or 1112 aligns to a first tapering profilediameter 1162 of the tapering profile and a chamber diameter 117 of theheat exchange chamber 11 aligns to a second tapering profile diameter1163 of the tapering profile (see FIG. 1, 2A, 2B, 5A or 5 b). The inflow132 of the heat transfer fluid 13 is guided into the heat exchangechamber interior 112. The guided inflow is distributed to a wide area ofheat storage material 121. By this measure a capacity of the heatexchange unit (heat storage material 121 which is located in the heatexchange chamber 11) can be utilized in an advantageous manner.

The transition area 116 is short. The transition area 116 comprisesdimension 1162 which is less than 50% of a heat exchange chamber length118 of the heat exchange chamber 11. The short transition area 116projects into the heat exchange chamber 11. The result is a shorttransition channel for the guiding of the inflow 132 into the heatexchange chamber interior 112 of the heat exchange chamber 11.

In order to adapt the heat exchange flow 13 the high temperature thermalenergy exchange system comprises a flow adjusting element 134. This flowadjusting element 134 is a blower.

Furthermore the heat exchange chamber 11 can comprise one or severalinlet openings 1111 and outlet openings 1112 as shown in FIG. 3.

The high temperature thermal energy exchange system 1 is additionallyequipped with at least one flow adjusting element 134. The flowadjusting element is an active fluid motion device (1341) like a bloweror a pump. Such a device enables a transportation of the heat transferfluid 131 through the heat exchange chamber interior 111 of the heatexchange chamber 11. The blower or the pump can be installed upstream ordownstream of to the heat exchange chamber 11.

In addition, at least one passive fluid control 1342 device like a valveis located upstream or downstream of the heat exchange chamber 11.

For the charging mode the downstream installation (installation of theadjusting device at the cold end of the high temperature thermal energyexchange system) is advantageous: Relatively cold heat transfer fluidpasses the flow adjusting device after releasing of heat to the heatstorage material. In contrast to that, in a discharging mode theupstream installation of the flow adjusting device is advantageous:Relatively cold heat transfer fluid passes the flow adjusting elementbefore absorbing heat from the heat storage material. For both modes,the flow adjusting element is located at the same position.

In case of vertical heat exchange chambers the inlet openings and outletopenings can be installed at the top and bottom (decreasing and avoidingnatural convection). Horizontal heat exchange chambers can have inletopenings and outlet openings on top and bottom (decreasing naturalconvection) or sideways (simple and inexpensive construction and simpleincident flow).

The heat transfer fluid 131 enters the heat exchange chamber 11 througha diffuser 1164. The diffuser 1164 comprises stones 1165 and is arrangedat the transition area 116 of the heat exchange chamber 11.

Furthermore the heat transfer fluid 131 can be liquid or gaseous, whichalso can be organic or inorganic.

In order to guide the heat transfer fluid 131 shutters and/or valves(passive fluid control devices) are used.

FIG. 2A shows a vertical heat exchange chamber 113 in a dischargingmode. The discharging mode direction 136 is oriented upwards.

FIG. 2B shows the vertical heat exchange chamber 113 of FIG. 2A in acharging mode. The charging mode direction 135 is directed downwards.

FIG. 3 shows a horizontal heat exchange chamber 114. Thereby two inletopenings 1111 are arranged above each other as well as two outletopenings 1112. These openings 1111 and 1112 are arranged at individualtransition areas 1166 of the heat exchange chamber 11. At least everyindividual transition area 1166 of the inlet openings comprises atapering profile. By means of the individual transition areas 1166,diffusers 1164 with stones 1165 are formed. For that, the transitionareas are filled with stones up to a third. Again: Measuring devices1500 for determining a charge status of the high temperature thermalenergy exchange system are distributed in the heat exchange chamber 11.

Depending on the usage and the demands, the capacity of the hightemperature thermal energy exchange system can easily be adapted (heatstorage material, dimensions of the heat exchange chamber, etc.). Forinstance, to increase the capacity of high temperature thermal energyexchange system the high temperature thermal energy exchange system isequipped with several heat exchange chambers as shown in FIG. 4.

Thereby the heat exchange chambers can be arranged in parallel,serially, in line, on top of each other and/or as single one. FIG. 4show such an embodiment with a parallel arrangement: Three heat exchangechambers 11 form together a common storage unit of the high temperaturethermal energy exchange system.

Referring to FIG. 7, the complete charging and discharging system 1000for a high temperature thermal energy exchange system 1 comprises one orseveral electrical heating devices 201, one or several machines tocirculate the working fluid such as blowers 211 or pumps 1341 and one orseveral heat exchange chambers 11. The electrical heating devices 200can be resistance heater 201, inductive heater or others. These devicesare connected by a pipe or ducting system 1001. The high temperaturethermal energy exchange system shown in FIG. 7 comprises a closed loop1005.

For the charging mode, the heat transfer fluid 131 is heated up fromambient conditions by the electrical heater 201.

Alternatively, the heating (partial heating or complete heating) of theheat transfer fluid is carried out with the aid of waste heat e.g. fromindustrial or power plant processes or from geothermal sources with orwithout an electrical heating device.

This charged heat transfer fluid is guided into the heat exchangechamber interior 112 of the heat exchange chamber 11 for charging theheat storage material. Thereby the heat exchange between the heattransfer fluid and the heat storage material takes place. With reference2000 the temperature front at a certain time of this charging process isshown.

The machine to circulate the heat transfer fluid 131 is preferablyinstalled upstream or alternatively downstream of the electrical heatingdevice or downstream of heat exchange chamber. Several heat exchangechambers 11 are combined for varying charge and discharge duration (notshown). Alternatively, just one heat exchange chamber 11 is used inorder to cover the required storage capacity.

For the discharging mode the high temperature thermal energy exchangesystem comprises one or several heat exchange chambers 11 mentionedabove, an active fluid motion control device 1341 to circulate the heattransfer fluid 131 and a thermal machine for re-electrification, whichcan be a water/steam cycle 1003. The working fluid of this cycle iswater and steam. The water/steam cycle 1003 has the function of adischarging unit 400. With the aid of the high temperature thermalenergy exchange system (heat exchanger) 1002 thermal energy of the heattransfer fluid is transferred to the working fluid of the steam cycle1002.

The different components of the high temperature thermal energy exchangesystem 1 are connected with a pipe or ducting system 1001. The flowadjusting element guides the heat transfer fluid through the heatexchange chamber of the high temperature thermal energy exchange system,thermal energy is transferred from the heat storage material 121 to theheat transfer fluid 131 and is transported to the thermal machines orfurther applications e.g. district heating, preheating of the dischargecycle, heating of different components of the high temperature thermalenergy exchange system etc. If the thermal machine is a water steamcycle, a steam generator, a heat exchanger or an evaporator, whichconsist of one or several units, the thermal energy is transferred towater to generate steam which is fed to a thermal engine to produceelectrical power as shown in FIG. 7. If the working fluid downstream ofthis thermal machine still contains thermal energy at a temperaturelevel higher than ambient, this energy can be stored in the same heatexchange chamber or in another heat exchange chamber.

The complete system with all components in charge and discharge cyclefor the high temperature thermal energy exchange system is shown in FIG.7.

In an energy system with high penetration of renewable energy theprofitability of fossil fueled thermal power plants suffers from lowoperation hours. This can lead to a complete shutdown of such plants foreconomic reasons.

FIG. 8 illustrates the power plant 100 with the steam cycle of a CCPPthat comprises a heat recovery steam generator. The gas turbine 2100 ofa combine cycle is removed and the remaining heat recovery steamgenerator is incorporated in the storage system, which is installed as aretrofit storage system in the CCPP. The exhaust gas channel of the gasturbine system is redesigned for a closed loop design of the storagesystem to recuperate the steam generator exhaust gas in the storage.

Main components besides the high temperature thermal energy exchangesystem 1 are a heater 501, a steam generator 502, a steam turboset 503,a condenser 504, a pump system 505 for the working fluid of theconventional power plant cycle.

In FIG. 9, a system is proposed that reuses the equipment of a coal,lignite, biomass, fuel surrogate, wood, oil or gas fired plant (perhapsnuclear, where a heat recovery steam generator is additionallyrequired). The combustion chamber 2200 or the grate stoker equipment aswell as the exhaust gas treatment system are removed from the system. Ifthe steam generator parameters and the design are suitable to beoperated with hot gas from the storage that comprises a lowertemperature than the combustion products of the removed combustionsystem the steam generator is used as it was designed. If not the steamgenerator is modified or even replaced with a heat recovery steamgenerator especially designed for the thermal storage system.

FIG. 10 shows a system layout where the combustion chamber 2200 remainsin the system and is used when fuel prices are low. This system canoperate in fossil fueled or in a storage operation mode. An appropriatevalve design in the gas path is required to guide the exhaust gas to theafter treatment system if necessary and to the environment or to realizethe closed loop when operating in storage mode.

FIG. 11 illustrates a similar system where the combustion chamber 2200is used to reheat the hot air downstream of the storage 1 to rapidlyincrease the power output. If gaseous fuels like natural gas, hydrogenor syngas are used the system is be operated in a closed loop. If theexhaust gases need further after treatment this is to be incorporated inthe closed loop or an additional flue gas system is needed to guide theexhaust gas to the environment.

In all proposed systems it is also possible to replace the steamgenerator by a steam generator designed for the storage application. Inthis case only the steam turboset, the condensing and the watertreatment system and auxiliaries such as e.g. switch gears areintegrated into the storage system.

If appropriate, the existing combustion chamber or grate stokercontainment is used as storage containment (heat exchange chamber) forthe heat storage material. If more storage volume is required parts ofthe material are integrated in an extra storage containment.

In FIGS. 10 and 11, an additional heat recovery steam generatorseparates the two gas paths of the original combustion system and thehigh temperature thermal energy exchange system if the exhaust gascontains chemical compounds that are not compatible with the heatstorage material or design. Alternatively a heat exchanger can be usedto extract the thermal energy downstream of the steam generator andguide it to the high temperature heat exchange system.

The system can be used or combined with any type of steam generator suchas Once Through Steam Generators (OTSG) or conventional drum boilers orsimilar.

Although the present invention has been disclosed in the form ofpreferred embodiments and variations thereon, it will be understood thatnumerous additional modifications and variations could be made theretowithout departing from the scope of the invention.

For the sake of clarity, it is to be understood that the use of “a” or“an” throughout this application does not exclude a plurality, and“comprising” does not exclude other steps or elements.

The invention claimed is:
 1. A power plant with at least one steam cycleand with at least one high temperature thermal energy exchange system,with at least one heat exchange chamber with chamber boundaries whichsurround at least one heat exchange chamber interior of the at least oneheat exchange chamber, wherein the chamber boundaries comprise: at leastone inlet opening for guiding in an inflow of at least one heat transferfluid into the at least one heat exchange chamber interior and at leastone outlet opening for guiding out an outflow of the heat transfer fluidout of the at least one heat exchange chamber interior; at least oneheat storage material is arranged in the at least one heat exchangechamber interior such that a heat exchange flow of the heat transferfluid through the heat exchange chamber interior causes a heat exchangebetween the heat storage material and the heat transfer fluid; and thehigh temperature thermal energy exchange system comprises at least oneretrofit component with which the power plant with steam cycle isequipped.
 2. The power plant with steam cycle according to claim 1,wherein heat exchange channels are embedded in the heat storage materialfor guiding of the heat exchange flow through the heat exchange chamberinterior.
 3. The power plant with steam cycle according to claim 1,wherein the thermal energy exchange system is equipped with at least oneflow adjusting element for adjusting the heat exchange flow of the heattransfer fluid through the heat exchange chamber interior, the inflow ofthe heat transfer fluid into the heat exchange chamber interior and/orthe outflow of the heat transfer fluid out of the heat exchange chamberinterior.
 4. The power plant with steam cycle according to claim 3,wherein the flow adjusting element comprises at least one active fluidmotion device which is selected from the group consisting of blower,flap and pump and/or the flow adjusting element comprises at least onepassive fluid control device which is selected from the group consistingof activatable bypass pipe, nozzle and valve.
 5. The power plant withsteam cycle according to claim 1, wherein the heat exchange chamber is avertical heat exchange chamber and/or a horizontal heat exchangechamber.
 6. The power plant with steam cycle according to claim 1,wherein the chamber boundary with one of the openings comprises atransition area with a tapering profile such that an opening diameter ofthe opening adapts to a chamber diameter of the heat exchange chamber.7. The power plant with steam cycle according to claim 1, wherein atleast two inlet openings are arranged vertically to each other and/or atleast two outlet openings are arranged vertically to each other.
 8. Thepower plant with steam cycle according to claim 1, wherein the heatstorage material comprises at least one chemically stable bulk materialwhich is selected from the group consisting of natural material andartificial material.
 9. The power plant with steam cycle according toclaim 1, wherein the heat storage material comprises at least onechemically and/or physically stable material.
 10. The power plant withsteam cycle according to claim 1, wherein the heat storage materialcomprises sand and/or stones.
 11. The power plant with steam cycleaccording to claim 10, wherein gas at ambient pressure is air.
 12. Thepower plant with steam cycle according to claim 1, which is equippedwith at least one heat charging unit for heating the heat transferfluid.
 13. The power plant with steam cycle according to claim 12,wherein the charging unit comprises at least one electrical heatingdevice which is selected from the group consisting of resistance heater,inductive heater, emitter of electromagnetic radiation and heat pump.14. The power plant with steam cycle according to claim 1, which isequipped with at least one measuring device for determining a chargestatus of the high temperature thermal energy exchange system.
 15. Thepower plant according to claim 1, wherein a closed loop is implementedand wherein the inflow comprises the outflow.
 16. The power plant withsteam cycle according to claim 1, wherein the power plant is a hybridpower plant with a thermal energy producing unit, wherein producedthermal energy from the thermal energy producing unit and/or storedthermal energy of the high temperature thermal energy exchange systemcan be used for driving the steam cycle.
 17. A method for manufacturingthe power plant with the steam cycle, with following manufacturing step:providing a power plant with at least one steam cycle and with at leastone high temperature thermal energy exchange system, with at least oneheat exchange chamber with chamber boundaries which surround at leastone heat exchange chamber interior of the at least one heat exchangechamber, wherein the chamber boundaries comprise at least one inletopening for guiding in an inflow of at least one heat transfer fluidinto the at least one heat exchange chamber interior and at least oneoutlet opening for guiding out an outflow of the heat transfer fluid outof the at least one heat exchange chamber interior; at least one heatstorage material is arranged in the at least one heat exchange chamberinterior such that a heat exchange flow of the heat transfer fluidthrough the heat exchange chamber interior causes a heat exchangebetween the heat storage material and the heat transfer fluid; and thehigh temperature thermal energy exchange system comprises at least oneretrofit component with which the power plant with steam cycle isequipped; retrofitting an existing power plant which comprises at leastone steam cycle with at least one part of a high temperature thermalenergy exchange system.
 18. The method according to claim 17, whereinfor the retrofitting a replacement of at least one steam cycle componentof the steam cycle by the high temperature thermal energy exchangesystem is carried out.